Pipe stabber head



Aug 4, 1970 L. J. WOOD 3,522,966

MPE STABBER HEAD Filed March 18, 196 2 sheets-sheet 1 .i INVENTOR. .l lm1/,4m Jn/Ma rma/EK Aug. 4, 1970 L. J. woon 3,522,966

PIPE STABBER HEAD Filed March 18, 1968 2 Sheets-Sheet 2 I N VEN TOR. fm/,4M L/ff ma United States Patent O 3,522,966 PIPE STABBER HEAD Leonard J. Wood, Pasadena, Tex., assigner` to` Global Marine Inc., Los Angeles, Calif., a corporation of Delaware Filed Mar. 18, 1968, Ser. No. 713,793 Int. Cl. B66c 1/62 U.S. Cl. 294-110 3 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION 'Field of the invention This invention relates to equipment for handling elongatedobjects suspendedl in an upright position and, more particularly, to pipe handling equipment useful in han-n dling pendulously supported lengths of drill pipe and the like in the drilling of Oil wells and the like to prevent such pipe from dangerous free swaying and swinging in the vicinity of a drilling rig platform.

-Review of the prior art During the drilling of an oil well with a rotary tool drilling rig, it is necessary periodically to connect additional joints (lengths) of drill pipe to the upper end of the drill string as the well is extended into the ground. In the process of connecting a pipe joint to the drill string, the joint is pendulously supported, in a substantially vertical attitude, from a traveling block which normally is provided in a hoisting derrick erected over a rotary table used to rotate the drill string and thereby a rotary drilling tool secured to the lower end of the drill string. Often the weight of a length of drill pipe is substantial.

Originally, suspended pipe joints were moved manually into position over and engagement with the upper end of the drill string projecting above the rotary table. Because of considerations of personnel safety, especially pertinent to operations performed on -oating vessels where such manual operations can be quite hazardous, and increased efficiency, several devices have been employed to constrain mechanically and move controllably a pendulously supported pipe joint about in a drilling rig when a joint is added to a drill string; such devices are also useful in handling multiple-joint sections of drill string when a tool is run into or out of a drilled hole, as when it is necessary to replace a worn or broken tool. Examples of prior devices, commonly called stabbers, are found in commonly owned Pat. 3,371,728 and in commonly owned, copending application Ser. No. 624,800 filed Mar. 21, 1967.

SUMMARY OF THE INVENTION The present invention provides a manipulative head for a pipe stabber, which head is especially well adapted for use in handling relatively large diameter, heavy drill pipes and similar cylindrical objects.

Generally speaking, the stabber head has a body and jaw means mounted thereto to be pivoted between rst and second positions relative to the body. The jaw means,

fice

in the first position thereof, substantially enclose the circumference of a length of drill pipe to prevent the pipe from moving significantly relative to the body. When in its second position the jaw means permit removal of the pipe from adjacent the body. Pivotally mounted and gravitationally biased locking means cooperate with the jaw means for securing the jaw means in the first position thereof.

Preferably, the jaw means include a lug which is connected to a rotatable shaft mounted to the body, and the jaw means include a pair of opposing jaw arms which are mounted for rotation about the axes normal to the shaft axis. A handle is connected to the lug and is arranged so that the weight thereof normally biases the lug into a jamming position between the jaw arms, the jaw arms in their first position being spaced to permit movement of the lug therebetween. The handle enables quick manual removal of the lug from between the jaw arms when it is desired to release a pipe length from constraint in the head.

This stabber head is rugged and simple inconstruction. It is also simple to operate and requires little or no maintenance.

BRIEF DESCRIPTION `OF THE DRAWINGS The above-mentioned and other features of the invention are more fully set forth in the following detailed description of a presently preferred embodiment of the invention, 'which description is` presented with reference to the accompanying drawings, wherein:

FIG. 1 is a top plan view, with parts broken away, of a stabber head according to this invention;

FIG. 2 is a plan view similar to FIG. 1 showing the jaws of the head closed about a length of drill pipe;

FIG. 3 is a cross-section view taken along line 3-3 of FIG. l; and

- FIG. 4 is an enlarged cross-section view taken along line 4-4 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1- and 3, a pipe stabber head 10 includes a body 12 defined by a pair of parallel, spaced top and bottom plates 14 and 1.6 which are joined to each other adjacent the rear of the head by a web 18. The top and bottom plates have a generally rectangular configuration, the web connecting these plates along one of their long sides. Each plate 14, 16 defines a generally circular recess 20 which is axially aligned with the recess in the other plate and which communicates with the edge of the plate opposite from the web. Corners 22 of the plate 14, 16, defined by the plate front edges and the recesses, are sufficiently spaced apart to enable a drill pipe 24 (shown in FIG. 2) to move freely in and out of the recesses along a line normal to web 18 when the stabber head is in use.

Bottom plate 16 additionally includes a generally rectangular recess 26 which communicates with adjacent recess 20 and which extends toward web *18 centrally of corners 22.

A pair of opposing, arcuately-shaped jaws 28 are disposed between the plates and have a width (vertical dimension) slightly less than the spacing between the plates. The jaws are pivotally mounted to the plates by pivot pins 30 which extend between plates 14 and 16. Pins 30 are located on opposite sides of recesses 20 and are disposed along a line passing diametrally of the recesses parallel to web 18. The jaws are mounted so that when their outer ends 32 are in abutment outwardly of recesses 20, as shown in FIG. 2, a preferably circularly arcuate inner surface 34 of each jaw is disposed coaxial with the axis of recesses 20 and is located radially inward from adjacent edge of the recesses. When jaw ends 32 are in abutment, their opposite inner ends 36 of the jaws are spaced apart a distance about equal to the width of recess 26 in a direction parallel to Web 18. The pivot pins which mount the jaws in the body project through an enlarged center boss 38 of each jaw which extends away from surface 34 of the jaw. Each boss, at a location opposite from surface 34 of the jaw, defines a flat surface 39 aligned parallel with adjacent pin 30.

A pair of leaf springs 40' are disposed between plates 14 and 16 and extend normal to web 18 outwardly of jaws 28. The springs are secured to the body adjacent web 18 and extend in planes normal to plates 14 and 16 and in cantilever fashion from the web toward the front of the stabber head body. The springs are biased into engagement, adjacent their unsupported ends, with the adjacent surfaces of bosses 38.

When the jaws are in an open position (see FIG. l) the springs engage corners 42 dened by bosses 38 at the ends of surfaces 39 adjacent jaw ends 32 to maintain the jaws in their open position and prevent their free pivotal movements about pins 30 into the closed position of the jaws shown in FIG. 2. To close the jaws, a force suicient to deflect the springs outwardly must be applied to the jaws to rotate them into the position shown in FIG. 2. Thus, the jaws are maintained open until a positive closing force is applied to them, usually by a pipe engaged in the head.

Similarly, when the jaws are closed, the springs engage surfaces 39 and restrain the jaws from moving toward their open position. A force must be applied to the jaws to rotate them about pins 30.

Stop bars 44 are disposed between plates 14 and 16 adjacent the opposite front corners of the plates to limit the maximum open condition of the jaws.

To prevent unintentional or undesired opening of the jaws when the stabber head is used to constrain or controllably move a length of pendulously supported drill pipe 24, a locking mechanism 46 is incuded in head 10. The locking mechanism includes a generally rectangular lug 48 which has a width transversely of the head slightly less than the spacing between inner ends 36 of jaws 28 when the latter are in closed position about pipe 24. The lug is mounted on an elongated shaft 50, the axis of which is transverse to that of pins 30 and parallel to web 18. The shaft is rotatably mounted in a pair of journal blocks 52 secured between plates 14 and 16. The journal blocks, shaft and lug are arranged so that the lug can be moved from a substantially horizontal position, shown in FIG. 2, into an inclined position, shown in FIG. 3.

When lug 48 is in its horizontal position, assuming the jaws are closed as shown in FIG. 2, it is disposed between ends 36 of the jaws and prevents the adjacent jaw end from moving toward each other as would occur if the jaws were moved from their closed position to their open position. Thus, the lug serves as a latch preventing the jaws from opening. W'hen lug 48 is in its inclined position, the lug is fully removed from the space intermediate jaw ends 36 and the jaws the-n can be moved into their open position once sufficient force is applied to the jaws to overcome the constraint imposed upon the jaws by springs 40. Recess 26 permits the lug to be moved from its jaw-latching position to its jawclearing position relative to body 12.

To provide a fully circularly cylindrical surface for restraining drill pipe 24 in stabber head 10, lug surface 54 opposite from shaft 50 is arcuately shaped to complete the circle deiined by the inner surfaces of the jaws in the closed position of the jaws.

A handle 56 is secured to the undersurface of lug 48 between surface 54 and shaft 50 to provide means for manually moving the lug from its jaw-locking to its jawnonlocking positions. The handle is arranged so that it extends substantially parallel to plate 16 adjacent an exterior of the head when the lug is in its jaw-nonlocking position. It is relatively long so that the center of gravity of the combination of the handle and the lug is always located rearwardly of the axis of shaft 50. Thus, the lug is gravitationally biased to move into its jaw-locking position. Also, the length of the handle provides a large mechanical advantage during manual operation of the locking mechanism such that the mechanism can be unlocked with relatively little physical effort.

A spring clip 58 (FIGS. 3 and 4) is mounted on the exterior surface of plate 16 and is aligned with handle 56 to engage the handle and retain it in a horizontal position. This enables the lug to be kept in a nonlocking position while drill pipe is moved into or out of the jaws, and eliminates the necessity of having to operate the handle of the locking mechanism when the drill pipe is moved out of the jaws and again when another pipe is moved into the jaws. The handle is cleared from clip 58 merely by manually pushing down on the portion of the handle which extends rearwardly of the clip, as shown in FIG. 3.

By gravitationally biasing the lug into a jaw-locking position, accidental opening of the jaws from shocks or vibrations to which the locking mechanism might be exposed, is prevented.

Instead of constructing the locking mechanism so that its own weight biases the lug into the locking position, other means such as springs (not shown), for example, can be relied upon to bias the lug into jaw-locking position. Similarly, spring clip 58 can be replaced by a suitable hook or latch, if desired.

Referring to FIG. 2, stabber head 10, in use, is removably secured via web 18 and bolts 64 to an extensible arm 60 of a supporting structure and extension mechanism 62 for the head. The supporting structure and extension mechanism may be arranged to reciprocate the head from over a rotary table to over a mouse hole in a drilling rig, or it may be arranged to move the head from over the rotary table to a pipe supply chute or the like. The supporting structure and extension mechanism may be arranged to move the head only reciprocably, or it may be arranged to swing the head horizontally along an arc as well as reciprocably. The above-cited patent and patent application show supporting structures and extension mechanisms with which head 10 may be used to advantage.

Turning now to the operation of the stabber head, assumed to be mounted on arm 60 for reciprocal movement in a horizontal plane toward and away from a rotary table in a ship-mounted drilling rig, let it be assumed the head is in the condition shown in FIG. 1 ready to engage a length of drill pipe 24. Leaf springs 40 cooperate with corners 42 on bosses 38 of the jaws to maintain the latter in an open position. A pipe is then moved between the jaws, either by operating mechanism 62 to move the head toward the pipe or by moving the pipe toward the head. Continued movement of the pipe relatively toward the head causes the pipe to engage inner ends 36 of the jaws and to move the jaws against the bias of springs 40 into their closed position shown in FIG. 2. An operator of the stabber then disengages handle 56 from the spring clip and lug 48 then moves by gravitational bias into the space intermediate the inner ends 36 of the jaws. The jaws are now maintained locked and the drill pipe is retained in the cylindrical passage defined by inner surfaces 34 of the jaws and surface S4 of the lug. Dangerous swaying or swinging of the suspended pipe is then restricted. Mechanism 62 can then be operated to controllably move the pipe as desired within the drilling rig.

To release the pipe from the stabber head, an operator of the stabber grasps handle S6 and swings it until the lug 48 is clear of the space between ends 36 of the jaws and the handle engages clip 58. The drill pipe then can be moved out of the jaws either by moving the pipe or by retracting arm 60, the jaws moving against the bias of springs 40 into their open position where they are kept until a pipe is again engaged in the head.

Head 10 is especially useful in handling drill pipe in drilling rigs mounted on iloating Vessels where wind and wave action can produce a moving work platform on which manual pipe handling activity is performed with diculty and -with considerable hazard. The head is also useful in shore-based drilling operations and in activities performed on Texas Tower type drilling platforms. The head is simple to operate and to construct, ecient and elfective in use, and requires little maintenance.

I claim:

1. Apparatus for handling pendulously supported drill pipe and the like in a drilling rig, the apparatus comprising:

a body defining a recess therein open to a boundary of the body and sized to admit the exterior diameter of a length of drill pipe;

a pair of elongate arcuately curved opposing jaws pivotally mounted to the body adjacent opposite sides of the recess, the jaws being congured to encircle a drill pipe disposed in the recess in a rst position of the jaws relative to the base in which corresponding one ends of the jaws adjacent the opening of the recess from the body substantially abut each other and in which corresponding opposite other ends of the jaws are spaced apart opposite from the opening of the recess from the body;

means mounting the jaws intermediate their lengths t0 the body for rotation about parallel axes;

a lug movably mounted to the body for movement between said other ends of the jaws in said rst position of the jaws for preventing movement of the jaws relative to the body into a second position thereof in which said one ends of the jaws are spaced across the opening of the recess a distance greater than the exterior diameter of a pipe disposed in the recess, the lug being mounted to the body for rotation about an axis disposed normal to said jaw pivot axes; and

means responsive to gravity coupled to the lug urging the lug into said space.

2. Apparatus according to claim 1 including an operating handle connected to the lug for moving the lug out of said space between said other ends of the jaws, the center of gravity of the combination of the lug and the handle being disposed laterally of said lug axis of rotation regardless of the position of the lug relative to the body.

References Cited UNITED STATES PATENTS 1,320,688 ll/19l9 Healy 294-110 3,068,036 12/1962 Doty 294-104 3,199,161 8/1965 Hamilton 294--110 X GERALD M. FORLENZA, Primary Examiner G. F. ABRAHAM, Assistant Examiner U.S. Cl. XR. 294-113 

